Rocket projectile



Dec. 11, 1956 J. R. JASSE ROCKET PROJECTILE 3 Sheets-Sheet l Filed Jan. '7, 1955 mimi Dec. 11, 1956 J. R. JAssE ROCKET PROJECTILE 5 Sheets-Sheet 2 Filed Jan. 7, 1955 Dec. 1l, 1956 J. R. JAssE ROCKET PROJECTILE 5 Sheets-Sheet 5 Filed Jan. 7, 1955 ROCKET PROJECTILE Joseph Raymond Jasse, Paris, France, assign'or to Societe Nouvelle des Etablissements Brandt, Pans, France, a

French body corporate Application January 7, 1955, Serial No. 480,565

Claims priority, appiication France January 21, 1954 6 Claims. (Cl. 102-49) An object of the invention is to provide a self-propelled projectile of considerably reduced weight, for a given offensive charge, relative to the weights of self-propelled projectiles of conventional type in which the offensive charge, which is explosive or otherwise, and the propellmg charge are disposed one behind the other in a stout body. The latter must be strong in the region of the explosive charge to obtain lethal fragmentation or high perforating power, and, furthermore, in the region of the self-propelling charge so as to withstand the pressure of the gases resulting from the combustion of this charge.

A further object of the invention is to provide a projectile in which the propelling charge is disposed in a thin container which is itself engaged in a longitudinal axial cavity provided in the offensive charge, which may be explosive or otherwise and which is in consequence situated in the annular space between the outer body and said container, a nozzle being provided at the rear of the body for the ejection of the propelling gases.

Owing to this arrangement, the centrifugal radial 'pressure due to the propelling gases is transmitted, through the medium of the container and the otensive charge, to the outer body; hence the container may be very thin and therefore very light.

Further features and advantages of the invention will be apparent from the ensuing description.

In the accompanying drawings given merely by way of example:

Fig. 1 is a longitudinal sectional View of a projectile embodying the invention, comprising a shell adapted to be tired by a ried-bore gun;

Fig. 2 is a longitudinal sectional view of the rear part of this projectile, this section being on a scale larger than that of Fig. l;

Fig. 3 is a partial cross-sectional view along line 3 3 lof Fig. 2;

Fig. 4 is ra longitudinal sectional view of a variant of the firing device for the propelling charge;

Fig. 5 is a longitudinal sectional View on a small scale of an improved rocket embodying the invention;

Fig. 6 is a partial longitudinal sectional view of the rear part of this rocket, this sectional view being on a scale greater than that of Fig. 5, and

Fig. 7 is a partial cross-sectional View along line 7-7 of Fig. 6.

In the embodiment shown in Figs. 1 to 3, the invention is shown to be applied to a shell adapted to be red from -United States Patent i a riiled-bore gun and which permits, for a given launchl ing or ring charge and therefore a given initial velocity of the projectile issuing from the gun, increasing this initial veloclty and thus obtaining greater range or a lower trajec'tory for a given range, a greater impact velocity or any Atithe forward end, the ogive comprises the usual open- 2,773,448 Patented Dec. 1l, 1956 ICE ing 2 for the purpose of screwing a ring 3 carrying conventional fuse F with its percussion device, its detonator 4 and, preferably, a first powder charge 5 contained in a compartment 6.

Screwed at the rear of the body 1, is a base comprising two parts. Part 7 is of -steel screw-threadedly engaged at 8 in the body 1 and comprises in the described example projections or studs 9 adapted to rotate the shell. The other part 10 is screw-threadedly engaged at 11 in the part 7. This part 10 of the base supports a nozzle T closed by an ejectable obturator-percussion device P. This nozzle and this device will be described hereinunder.

Further, secured on the part 7 of the base is a thin longitudinal container 12 of dead soft steel. These two elements are brazed together at 13. The container 12 is surrounded by an -athermanous layer 14 which is 2 3 mm. thick. This heat insulating layer may be composed of either a docking of asbestos or a layer containing substances such as talc or alumina Iagglomerated by a syn thetic resin.

The annular space between the body 1 and this protected container 12-14 is iilled with the offensive charge, for example an explosive charge 15. This charge 15 is introduced, for example poured, through the front opening 2 of the body 1.

As can be seen, the charge 15 forms an axial cavity 16 which is lined with the protected container 12 and is closed at the rear by the part 10 of the base, the nozzle T and the obturator-percussion device P. This cavity forms a combustion chamber for a propelling charge 17. A characteristic of this propelling charge 17 is that it has only one inner combustion surface 18. Its outer surface is covered with a varnish 19 which prevents combustion. In order to increase the inner surface 18, the inner periphery of the cross-section of the propelling charge 17 is, for example, in the form of a six-pointed star.

A slight clearance 20 of the order of 0.2 mm. is provided between the propelling charge 17 and the container 12.

Disposed forwardly of the charge 17 and adjoining the closed front end of the container 12 is an insulating and yieldable cushion 21 (Fig. l) for example of a plastic material notably of the polyamide type. Gripped between this cushion 21 and the propelling charge 17 is a firing cartridge 22 composed for example of a celluloid envelope filled with black powder.

Bearing against this cartridge 22 is a tube 23 of celluloid or similar material which is disposed in the central cavity of the charge 17 and is adapted to conduct the ame issuing from the firing device constituted by the obturator-percussion device to the cartridge 22. This tube. is engaged in the nozzle T and bears against the device P.

The exhaust nozzle T comprises two parts: a nozzle collar 24 of graphite, fitted into a bore 25 formed in the part 10 of the base, and a nozzle nut 26 which forms a diverging means and is screw-threadedly engaged in the part 10 of the base.

Clamped between the part 10 and the nut 26 isv the periphery of a washer 27 of low shear resistance'which supports the unit comprising the obturator-percussion device and the tiring device P.

This device P comprises (Fig. 2) a body 28 and a plug 29 which are screw-threadedly engaged and clamp the inner portion of the washer 27. The body 28 comprises va bore 30 in which is slidable a tiring pin 31 urged for- 3 38 is clamped between Ythe 'charge 17 and the elements "n'd 24 f'th'e bse 'aidtlil'o T S 'S V'lb *Close all h rear in a strictly hermetic 'fmanner the space 20 between the charge llwand its container. r I

,The projectile oper'fes theA f llbwng 'menten .the miams ifs fired u aannam.; @breech mah@- nsm and its 1own propelling charge.4 ,Unde'rftlie effect of the acceleration in this `gun the rin'g pin l Iconpresses :thespring 32. The projections for' studsV 9 are guided by the riding in the bore and impart to the :projec'tileits stabilizing rotation. Y y j In the -course ofthe travel through the gun `theo'bbturatorpercussion device is 'applied by the prevailing pressure Vagainst the diverging means 26 of theA nozzle and theseal- `ing'rirlg36 assures an airtight connectionbetween the plug 2 9ja'ndthe`v partv 10 of the'base. The gases of the tiring powder therefor'ercannot in any way enter the ,projectile and cause its premature explosion.A v Y y However, an account of the fact that the projectile is caused to rotate, the weights or masses 33 fare urged radially outwardly and open the split 'keeper ring 34 thereby freeing the firing pin. Thus When `the projectile issues fromI the gun and ceases to accelerate, andeven decelerates owing to the air resistance the freed firing pin 30-is thrown :forwardly by the expansion of the spring 32 onto the relay-primer. The primer 35 functions, the relay 35a ignites and the flames travelralong the tube 23 and ignite the cartridge 22.

Y As soon as the cartridge 22 is ignited it ignites in turn l'the propelling charge 17. Pressure rises in the combustion chamber and at a given pressure the Washer 27 shears and the device P is ejected at a pressure below the normal working pressure in the combustion chamber.

Thetlin container 12 which is of dead soft steel 4(having littlestrength but a high elongation) and whose function isysiniply to provide a partition between the combustion chamber and the explosive compartment, expands under the eiect of the internal pressure and exerts a -pres'sure on the explosive 15 enclosed b y the body 1.

The pressure prevailing within the container 12 may therefore be considered as transmitted to the wall 1 through the explosive 15. Actually, the forces developed between the container 12 and the body 1 are fairly cornp'lex. The body 1 of the projectile is subjected to the pressure prevailing in the combustion chairiber only if the explosive charge is liquid, which is fairly rare. Indeed, when under pressure, explosives of conventional type, if they do not behave exactly in the manner of solids, behave vin a manner similar to 'earths having a certain cohesion.

The body 1 under these conditions Would be subjected at the rno's't lto a unit pressure p:

T'. y R

Where 2P is vthe pressure prevailing in 'the container 1'2, vr is 'the radius of the cross-section ofthis container and VR is the outer radius of the 'body 1 of "the projectile.y

The actual value of the pressure lp would be furtherrmore, vless than Vthe explosive 15 through the aperture 2 into the space left free for purpose, it is advantageous toy test the combustion chamber by filling it with liquid under presst ne. A Injthe v region of anypossible considerable lpipe-in l"the explosive' the container y12 would swell and even split and the liquid would then enter the explosive 15. By having IlOD-lidtigljt 'CDDEG''I'I t '011e 'O'f the 'cbling points 2 or 8 it would be possible to ascertain this leakage. This test also permits ascertaining any defect in the fluid-tightness of the container 12 or of its connection with the base.

It will be observed that inasmuch as lthe mass of propelling powder 17 burns solely from `within outwardly, since'the varnish 19 protects its outer surface, this powder acts as the main heat insulator until the end of combustion. The insulating layer 14 disposed -on the -outside of the container 12 is merely an additionalwsecurity the need for which is lessened by the presence of thec'le'arance 20. By means Yof this clearance it is possibleto `avoid a cracking of the propelling charge 17, which could occur if the latter were glued, by way of the combustion-preventing layer 19, to the container 12, and in consequence avoid risk of premature explosion of the projectile rwhich could result from either an accidental and above all premature arrival of llames in contact with lthe case-or excessive pressure due to thepbu'rning up, of a l sur'f'aee which should have been protected by the preventive layer.

This clearance 20 permits, furthermore, a smallamoiint of gas issuing from the propelling charge -to ll the space 20 from the forward end as soon as the charge 17 is ignited; but these gases encounter, in this .space alarge cold mass and, in view of the heat capacities involved, they are instantly cooled thereby. As thehemetic sealing at 38 of the space 20 prevents any .circulation of gas, the cooled gases stagnate therein and thus contribute to the heat insulation of the peripheral y*charge 15`.

y It will be noted, moreover, that ythe acceleration and the pressure exerted on the cake of powder 1 7 by `the yieldable cushion 21 ensures that the seal 33 isgripped between this cake and the part 24 of thefnozzlen' u It should be mentioned that the described` arrangement assures an excellent behaviour of the .charge v 1-.7 without a grid. Its seating on the 'nozzle T is -'very large and it is insulated from the gaseous current. Furthermore, the charge 17 is perfectly held in ,place during the high acceleration in the gun; Yit .srnerly subjected to compression without any riskof.igniting. g

If need be, the case 12fand its outer coatingy.14may be replaced by a container of a plastic material which is sufficiently Vplasticized and resistant, in which vcase the atherrnanous .properties of the plastic material render it suflicient in itself Without need for additional sprovisions.

j Fig. 4 shows a Variant P1 vof the obturatorpercussiqn device. This variant comprises a pyrotechnic delay-de vice. v

The body 28a of the obturator merely com-prisesfa passageway for the passage of the llame, formed in the following manner. An aperture 39, containingashighlycompressed black powder ora tracer composition 40, communicates through a narrow vent 41 with :another aperture 42 which is also lled with packed vblaclcpowder 43. This device is -obviouslyyadjustable by the choice of the size of the vent 41which formsa delay. This delay may amount to several seconds. Itis adapted to permit damping of the nutation of the projectile'at the moment of firing before the propelling charge :has been ignited. it is knownthat the slightest..nutation Iof a self-propelled projectile is harmful toiiring ,precjs iqn..

Figs. l5 to 7, show the application of the Ainvention-to a self-propelled rocket. The arrangement-issubstantially identical to the preceding arrangement, at least concerns the shaped steel body 1b, the base 7b, the container 12", the outer insulating ulayel ,14?, the fexplosive 15lo andthe propelling charge f175 with'vitsscombus'tionpreventing varnish 19h. A conventional ',iiozzle T2 is screw-threadcdlyfengaged in the'b'ase 7l?. f-Bisposed in the ring of this nozzle is an electric ringzsys'teml'.'

Although specilic yembodiments fof the invention have been described it must be understood that many changes and modifications may be made therein without departing from the spirit of the invention or the scope of the appended claims.

Having now described my invention what I claim as new and desire to secure by Letters Patent is:

1. Self-propelled projectile comprising in combination: a hollow strong outer body the cavity of which communicates with the exterior at the front end through an axial tapped hole, this cavity extending up to the rear end of said body where it terminates in a tapped portion; a conventional fuse fixed in this axial hole in such manner as to extend partially into said cavity; an anular base fixed to the rear in said tapped portion of the cavity; an axial nozzle fixed in said base for connecting said cavity with the exterior; an olensive charge in intimate contact with the entire surface of said cavity and with the portion of the fuse which extends into said cavity, this fuse being adapted to ignite said charge at the required moment and said charge comprising `a blind axial longitudinal hole open at the rear in front of the entrance of said nozzle; an airtight thin container which is incombustible, provided with a front end and open at the rear, disposed in said longitudinal hole, the shape of which it matches exactly, and in intimate contact over its entire outer surface with said offensive charge; a propelling charge disposed in said container, an empty annular space being provided between said container and the propelling charge; an elastic device between the front end of said container and said charge for applying the rear end of the latter against the front annular face of said nozzle around the passageway in the latter; a firing device for igniting said propelling charge; and a sealing joint interposed between the rear ends of said container and said charge and, moreover, against the concentric front faces of said base and said nozzle.

2. Projectile as claimed in claim l, wherein said propelling charge is tubular and said sealing joint is annular.

3. Projectile as claimed in claim l, wherein said base comprises an inner annular member and an outer annular member screw-threadedly engaged, the outer member being screw-threaded externally for the purpose of its screw-threaded engagement in the tapped portion of the cavity of the outer body and, comprising a stepped hole the larger rear part of which is tapped at least partially for receiving the inner member which is screwthreaded whereas the forward portion of this hole forms an inner flange which partially spans the inner member in the centripetal direction, the container containing the propelling charge terminating at the rear in an outwardly extending transverse seating portion, and the latter and the periphery of said sealing joint being gripped between said ange and the forward face of said inner part of the base.

4. Projectile as claimed in claim 3, wherein said 'container is welded in a sealed manner to said outer member of the base.

5. In a gyroscopically stabilized shell adapted to be launched or fired by an auxiliary charge in a ried gun and thereafter continue its trajectory in a self propelled manner, said shell comprising an outer body which is provided with a rear base and contains an offensive change and a propelling charge, the provision at the rear of said body of a firing device for said propelling charge, said device comprising in combination: forward and rear members, these members being connected in an ejectable manner to said base and being provided with axial apertures in alignment with one another, the aperture in the forward member being a throughway aperture and that in the rear member being a blind aperture and the forward member comprising a plurality of radial apertures which communicate with said axial aperture; a primer and a relay xed in the forward end of said axial aperture, the primer being disposed at the rear of the relay; a movable firing pin in said axial aperture at the rear of said primer; an elastic device between said ring pin and the end of said blind axial aperture for projecting said firing pin onto said primer; locks movable in said radial apertures for maintaining said firing pin in a rear retracted larming position in opposition `to the action of said spring and an elastic device for maintaining these locks in their operative position so long as the centrifugal force exerted on these locks is insufficient to retract them.

6. In a gyroscopically stabilized shell adapted to be launched or ired by an auxiliary charge in a riied gun and thereafter continue its trajectory in a self propelled manner, said shell comprising an outer body which is provided with a rear base and contains an oensive charge and a tubular propelling charge, the provision at the rear of said body of a firing device for said propelling charge, and at the forward end of said propelling charge of an inflammable cartridge adapted to be ignited by said tiring device, said device comprising in combination: a forward and a rear element, these elements being connected to said base in an ejectable manner, said forward element comprising an axial aperture having a forward portion and a rear portion connected by a throat portion forming a delaying means, a powder charge which fills the rear portion of this aperture and is adapted to be ignited when the projectile is launched by said auxiliary charge of the gun; and another forward powder charge filling the forward portion of said aperture, a tube of an inflammable material engaged in said axial aperture and extending between said forward powder charge and said tiring device.

References Cited in the le of this patent UNITED STATES PATENTS 958,990 Bourdelles May 24, 1910 2,145,508 Denoix Jan. 3l, 1939 2,206,809 Denoix Iuly 2, 1940 2,246,429 Brandt June 17, 1941 2,693,757 Brandt NOV. 9, 1954 2,728,295 Rubin et al Dec. 27, 1955 FOREIGN PATENTS 502,560 France Feb. 24, 1920 659,758 Great Britain Oct. 24, 1951 

